What is artsonia-mcp CLAUDE.md?

A repository-specific instruction guide for Claude Code, an AI coding assistant. It explains an Artsonia MCP server, which connects the assistant to children’s artwork portfolios on Artsonia, including its login, scraping, tools, and two transport modes.

Use it when working on this Artsonia server, especially its client, authentication, transport modes, portfolio features, or confirm-gated write operations.

It gives the coding assistant the project’s architecture and authentication rules so changes fit the existing design and handle its private website session correctly.

How chrischall/artsonia-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to chrischall/artsonia-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/chrischall/artsonia-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/chrischall/artsonia-mcp

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/chrischall/artsonia-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/chrischall/artsonia-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/chrischall/artsonia-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/chrischall/artsonia-mcp/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/chrischall/artsonia-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/chrischall/artsonia-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 4,847 This file is loaded in full into every session.

When invoked 4,847 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.04847	$0.04847
Opus 5	$0.02423	$0.02423
Sonnet 5	$0.00969	$0.00969
Haiku 4.5	$0.00485	$0.00485

Measured 10d ago against content hash f21745216162, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

artsonia-mcp CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 162 lines

How it starts

The opening of the file, as written. The whole thing — 162 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

TL;DR

MCP server for Artsonia (artsonia.com — kids' artwork portfolios). Cookie-session archetype: there is no public API, so the server logs into the parent/fan website with a username + password, harvests the resulting HttpOnly session cookie, and scrapes/POSTs the member pages. 15 tools across students, portfolio/artwork, comments, fans, teacher feedback, awards, account profile, image downloads, and a small set of confirm-gated writes.

Two transport modes, selected by ARTSONIA_TRANSPORT:

fetch (default, direct) — Node fetch against the site. The server owns the session: AuthManager runs the username/password login (POST /members/login.asp), keeps the cookie jar, and re-logs-in once on expiry.
fetchproxy (optional, browser-session) — requests ride the user's already-signed-in browser tab via @fetchproxy/server. The browser carries the session, so the server-side login is skipped entirely (usesBrowserSession = true). No ARTSONIA_USERNAME/PASSWORD needed in this mode.

Auth resolution

src/auth.ts owns the username/password login and the cookie session. It delegates the single-flight login + invalidate/re-login + one-replay-on-expiry to the shared CookieSessionManager from @chrischall/mcp-utils/session, typed over ArtsoniaResponse so the custom transport's response flows through withSession() untouched.

Env vars: ARTSONIA_USERNAME + ARTSONIA_PASSWORD (required in direct mode), ARTSONIA_TRANSPORT (fetch default | fetchproxy), ARTSONIA_WS_PORT (fetchproxy WebSocket port override; default 37149 — a shared fleet port, do NOT change), ARTSONIA_INLINE_DOWNLOADS (1/true/yes/on ⇒ inline image downloads; unset/false ⇒ disk — see "Download I/O" below), ARTSONIA_SESSION_CACHE (false disables the on-disk session cache; default on, direct mode only) and ARTSONIA_SESSION_FILE (override the cache path; defaults to $MCP_DATA_DIR/.artsonia-mcp/session-<user>.json, one file PER USER so createDirectClient callers do not clobber each other).
Deferred config error: the client is a module singleton constructed in src/client.ts (NOT index.ts), so the server boots and answers the host's install-time tools/list probe even with no creds. The missing-creds error is cached as a permanent error (CONFIG_ERROR_MARKER) and only surfaces on the first tool call — every later ensure() rethrows it rather than retrying a login that can never succeed.
Login success marker: doLogin() POSTs Username/Password/TargetUrl=/members//Action=login with redirect: 'manual' and treats a 301/302 whose Location is NOT login.asp (plus a non-empty cookie jar) as success. Magic-link-only accounts are unsupported.
Expiry heuristic (looksUnauthenticated): Artsonia expires by redirecting/rendering back to the login page (NOT a 401). Detected from the final URL, login-page body markers (You need to log in / Parent (or Fan) Login), or a manual 3xx Location pointing at login.asp.

Read the full file on GitHub · 162 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

10d ago First seen · 162 lines · 4,847 tokens per session scan A f21745216162

Subscribe to this mod's changes

artsonia-mcp CLAUDE.md is an instructions file published in the GitHub repository chrischall/artsonia-mcp (0 stars, last pushed today), licensed MIT. It adds 4,847 tokens to every session, about $0.0242 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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artsonia-mcp: Instructions file for Claude Code